I just re-seated the head on my 2.1l Renault turbo diesel and have a question. If I turn it over by hand without the valves opening at all, I can hear air hissing out the bottom of the cylinders. Is that a sign of worn piston rings or do I need to re-do the head gasket again? -- Stephen T. Kraus Jr. Home: (423)326-9359 UB3RATL4Sf00 at gmail.com;